The CAS Registry Mumber 122700-67-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,2,7,0 and 0 respectively; the second part has 2 digits, 6 and 7 respectively. Calculate Digit Verification of CAS Registry Number 122700-67: (8*1)+(7*2)+(6*2)+(5*7)+(4*0)+(3*0)+(2*6)+(1*7)=88 88 % 10 = 8 So 122700-67-8 is a valid CAS Registry Number.